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If it actually comes up, just play mainlines.  Mostly though, it won't come up.  You'll face 90% d-pawn specials and exchanges.

Despite the name I thought that the Benko Gambit was considered sound and fairly positional. I am surprised that nobody has recommended it. Am I wrong?

These things are true, but are not the same thing as solid.

Boris Avruhk's 1. d4: A Grandmaster Repertoire basically refutes the Benko Gambit. Use at your own risk.

Avrukh recommends theoretical knowledge of over 20 variations, just in the mainline, branching out starting with move 13.  At the ends of half of them, he tentatively gives +/=, suggesting black has "some compensation" but that he has a slight preference for white.

In one secondary branch, he purports to have found his solution with a novelty at move 18, which if you play nothing but the Benko for the rest of your life, you will never reach even once unless your opponent is Avrukh himself.

It's silly to suggest it "basically refutes" the Benko, but even if it did, the refutation would be meaningless.